Lactobacillus casei Zhang是1株筛选自发酵酸马奶,并具有耐酸等益生特性的益生乳杆菌。该研究利用蛋白质组双向电泳,比较了其在pH值为7.0和5.5的培养液中分别生长至对数生长期中期的蛋白质组表达差异。结果表明,有11个蛋白质点表达发生明显变化,经过基质辅助激光解吸/电离飞行时间质谱鉴定,其中有3个表达增强的蛋白质点分别鉴定为翻译因子(EF-Tu),N-乙酰氨基葡萄糖-6-磷酸脱醛酶(NagA)和小热休克蛋白(sHsp)。酸胁迫可诱导乳酸菌产生复杂的酸应激反应,涉及不同的代谢调控途径。

Lactobacillus casei Zhang,isolated from traditional home-made koumiss in Inner Mongolia of China,has been considered as a new probiotic bacterium for its characteristics,especially acid tolerance.Proteomics researches were carried out to identify proteins expression of Lactobacillus casei Zhang grown at different pH values of pH 7.0 and 5.5.Cytosolic proteins of mid-exponential phase were resolved and further analyzed by two-dimensional gel electrophoresis.As results shown,eleven protein spots were found showing statistically significant differences.Three of total protein spots were identified as EF-Tu,NagA and sHsp using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF/MS),indicating the complex response of lactic acid bacteria to acid stress.